Any question answered...

any info is helpful at all (re: foxton's). trying to start finding a place from canada is not easy. showing up in london and living in a hotel/cheap apartment for 2 weeks looks like its the only way its going to work.

To be fair I think that would be the best plan, short term rents/lets are more expensive but, it would give you opportunity to get a proper feel for the lay of the land, including the best transport links for where you guys need to be going on a daily basis. Everyone has a horror story that they can tell about a friend or a friend of a friend ;) etc. who has moved to London for the first time and was taken for a ride by a letting agent. The big problem with this is that they will ask you to sign a short assured tenancy agreement for 6 to 12 months, if you want to get out of this it is difficult as it is designed to protect the landlord and most of the time you will have to pay rent until the flat is re-occupied or the lease runs out, pay for advertising costs and pay for rent in the new flat you move to.

I would offer to let you couch surf at my place but:
a. it is too small.
b. I think I am right in saying you have a family, so its not ideal for you.
c. I live on the other side of London to where you are looking.